There are many duties to carry out on a dairy farm and some of these have to be carried out on specific times. For instance, when milk has been collected from a milk storage tank by a milk lorry, e.g. every second day, the milk storage tank has to be cleaned. Suitably, the rest of the milking system is then cleaned along with the milk storage tank.
Due to hygienic requirements the milking system comprises a milk filter, which milk filter further has to be cleaned or replaced by a new milk filter regularly, generally, three times per day and night. Suitably, the milk filter is renewed or replaced when the milking system has been cleaned. As the milk filter is renewed or replaced regularly, some of the renewals or replacements will need to be carried out at odd working hours, e.g. during the night.
It is therefore desirable to perform the renewal or replacement of the filter at least partially automatically such that the operator of the milking system need not attend the milking system during these odd working hours.
In EP 0653153 A1 a milking machine is disclosed provided with one or more filtration devices, each being provided with a filter, for filtering milk. When the milking machine is cleaning a cleaning liquid is led through a filter in a direction opposite to that in which the milk passes during filtration. A disadvantage of such a filtration device is that the back flush cleaning involves risks of catching dirt in the filter, which thereafter may come loose during milking and contaminate the milk.
Further, EP 0653153 A1 describes that several filter devices, connected by a piping, may be used, wherein one filter device may be renewed while another one is used for filtering milk. A disadvantage of such an arrangement is that the piping connecting the filters necessarily include corners, branches and recesses, may be difficult to clean. Further, such filter devices have to be renewable, and thus disposable filters are not suitable to be used.